[EM] Explaining PR-STV

[Markus Schulze]

Hallo,

I would explain proportional representaion
by the single transferable vote as follows:

1) Each voter gets a complete list of all
candidates and ranks these candidates in
order of preference.

2) Suppose M is the number of seats and
V is the number of votes. If there is a
set of X candidates such that strictly more
than (Y*V)/(M+1) votes strictly prefer
each candidate of this set to each candidate
outside this set, then at least min{X,Y}
candidates of this set must be elected.

Markus Schulze